Mexico’s National Human Rights Commission will investigate the Jan. 23 murder of a journalist in Guerrero. It is the first killing of a journalist in Mexico this year.

Miguel Ángel Guzmán Garduño, an opinion columnist for the daily paper Vértice, was found dead in his Chilpancingo home after being robbed of his possessions, according to Diario de Guerrero. Authorities say Guzmán died from blows days before being discovered. The crime’s motive remains as yet unknown but authorities said the probable motive was the theft of electrical and domestic appliances and his car.

Guzmán was a primary school teacher, as well as a journalist. He had also worked as the head of public relations for the state of Guerrero’s public sector workers’ union (SUSPEG).

“Federal and state authorities have the obligation to conduct a timely and effective investigation into threats against journalists in order to counter impunity and stop the deterioration of freedom of expression,” the CNDH said.

Mexico’s human rights ombudsman Raúl Plascencia Villanueva ordered his officials to visit the crime scene to analyze what happened and conduct their own investigation.